Anterior Hox Genes: Evolution by Birth and Death With Developmental Constraints

Hox genes represent an important gene family that is involved in the segmentation pattern and identity of the segments during the formation of the body plan in metazoans. For many years, several studies have sought to establish a correlation between the evolution of these genes and the evolution of large groups of metazoans. Here, we use publicly available sequences of Hox gene clusters to reconstruct the evolutionary history of anterior Hox genes. We show that information harbored by these genes, in part, reflects the evolution and diversification of most animal archetypes, but in many cases, there were conflicts between the evolutionary history of some genes and the history of large groups, these cases may have occurred due to specific and similar selective pressures in relatively distant groups, which may have led to evolutionary convergences. Our findings also reveal that the evolution of Hox genes (and clusters) as a multigene family is consistent to a birth-and-death model constrained by development, where there is a trade-off between a relatively fast gene turnover and their central developmental roles